I don't know.  Dreamcast came out first and had a significant head start.
Basically, though, Sony probably doesn't have a choice.  Even if their hardware can be ready in time for a Holiday '05 launch they can't launch without software.  They need to have a slew of titles available, including AT LEAST one killer app.  they also have to be prepared to have more software releasing with regularity, at least a few big titles per month.  If they rush the development of the software and debut with a bunch of unpolished crap they will practically be asking to lose their place as market leader.